Build Your Own Assay Tools

Complete Set of Tools to Build Your Own Stable Cell lines and Cell-Based Assays

Take advantage of DiscoverX’s robust proprietary Enzyme Fragment Complementation (EFC) technology to develop your own stable cell lines and cell-based assays to study protein-protein interactions, compound-target engagement, cytotoxicity, protein translocation, and much more. Design your own workflows and utilize engineered parental cell lines, retroparticles, and plasmid vectors to introduce your own target of interest and create cell-based assays for multiple applications.

  • Any Cell Background – Make your own stable β-arrestin recruitment or cytotoxicity cell-based assays in any dividing cell type with PathHunter® or KILR® retroparticles

  • Simple Protocols  – Detailed, step-by-step instructions with flow-charts and graphics to simplify assay development 

  • Complete Kit – Ready-to-use target engagement kit includes all the reagents you need to get you started

  • Flexible Solutions – Utilize any of our cell-line expression vectors to introduce mutants, make modifications, or study unique orthologs or isotypes


Easy-to-Follow Protocols for Cell-based Assay Generation Using PathHunter® Parental Cell Lines and Plasmids


Workflow protocol schematic to show how to generate an EFC cell-based assay. Start with an engineered PathHunter® parental cell line containing EA to study subcellular translocation (e.g. including membrane receptor trafficking), SH2 recruitment for receptor kinases, or GPCR β-arrestin recruitment. The specific parental cell line chosen determines the assay type. Then create an ED-tagged target protein plasmid followed by transfection of this plasmid into the parental cell line containing EA. Perform antibiotic selection, detect the level of expression of the two fusion proteins (optional), and perform the desired assay in the presence of a ligand.



Rapidly Create β-Arrestin, Tyrosine Kinase, and Translocation Assays Using Engineered Cells

PathHunter® Parental Cell Lines

Utilize engineered PathHunter parental cells to rapidly develop β-arrestin recruitment, SH2-protein recruitment, or translocation EFC cell-based assays after introducing your protein of interest. These parental cell lines provide the ability to study β-arrestin recruitment with your favorite GPCR, analyze tyrosine kinase activity and SH2-recruitment, or investigate trafficking of your target protein to the plasma membrane, nucleus, or endosome.

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Generate Your Own Stable GPCR Cell Lines for Monitoring Calcium or cAMP Accumulation 

ChemiBrite™ andChemiScreen™ Parental Cell Lines

Engineered, stability-tested cell lines in a variety of cell backgrounds ideal for recombinant GPCR expression with or without various coupling status (Gα15, Gqi, Gqo, Gqs). Use with chemiluminescent or fluorescent assays to analyze agonists, antagonists, and modulators of your GPCR target to study functional response. Ready-to-Assay™ parental control frozen cells also available.

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Create Target-Specific, Stable β-Arrestin Cell-Based Assays


PathHunter β-Arrestin Retroparticles

Make your own stable β-arrestin cell lines and EFC cell-based assays for any target in any dividing cell type. Use the assays to analyze the activation and desensitization of GPCRs and regulation of other signaling molecules such as protein kinases that involve β-arrestin recruitment.

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Design Target Cells Expressing Receptor Antigens of Choice to Study Cytotoxicity

KILR® Retroparticles

Generate target cells, expressing natively expressed or engineered surface antigens of choice, in the cells of your choice, to measure target cell death in co-cultures. These designer cytotoxicity assays allow for studying antibody dependent cell-mediated cytotoxicity, complement dependent cytotoxicity, antibody dependent cell phagocytosis, and more.

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Clone Your Protein of Interest into EFC-Based Cloning Vectors

PathHunter ProLink™ and ProLabel® Cloning Vectors

Utilize pCMV Mammalian cloning vectors to clone in your protein of interest with ProLink or ProLabel, as an N- or C-terminal tag, and subsequently transfecting into a cell line to create EFC cell-based assays.

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EFC Vectors Expressing Targets Found in DiscoverX Cell Lines

Expression Vectors

Introduce an expression vector into unique cell types to create EFC cell-based assays. These vectors include a protein target found in our DiscoverX cell-based assays tagged with a ProLink or ProLabel sequence.

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Easily Make Your Own Compound-Target Engagement Cell-Based Assays

InCELL Pulse™ Target Engagement Starter Kit

Develop cellular InCELL Pulse compound-target engagement assays to measure inhibitor cellular potency against user-defined protein targets of interest. These assays apply EFC and ligand-dependent thermal stabilization of target proteins such as protein kinases, methyltransferases, and hydrolases. Employ the simple protocol with minimal hands-on time to obtain quantitative inhibitor EC50 values in a native cellular environment.

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Create Your Own Functional GPCR CHO-K1 EFC-based Cellular Assays

PathHunter® GPCR eXplorer Kit

Utilize a, easy-to-use protocol and reagents to build on-demand functional GPCR assays in just 3 simple steps – Clone. Transfect. Read. This optimized EFC-based platform provides a simple method to explore the functionally of various GPCR mutants or isotypes, or any of your favorite GPCRs.

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Custom Proteins, Cell Lines, and Cell-Based Assays Developed For You

When existing off-the-shelf solutions are not enough or a developer is not available, trust Eurofins DiscoverX to develop a solution that will product the quality results you expect. These programs include custom protein production through cell line and assay development. Cell lines and cell-based assays include unique backgrounds, orthologs, and mutants as well as creation of custom cellular (functional or binding) or biochemical assays for drug discovery, process development, and basic research. Learn more


Create Your Own Cell-Based Assays to Study Receptor Tyrosine Kinase Function  Watch Webinar
Creating Cellular Target Engagement Assays for Diverse Kinases Using InCELL Pulse™ Watch Webinar
Create Your Own InCELL Pulse™ Cellular Compound-Target Engagement Assay Watch Webinar

Blog Articles

Do-It-Yourself: Benefits and Challenges of Creating Your Own Cell-Based Assays Read Article
Ideal Methods to Study Cellular Transport of Membrane Proteins Read Article
Why Study GPCR Arrestin Recruitment? Read Article
Critical Needs in Cellular Target Engagement Read Article


GPCR Products List  PDF Download
eBook: Insights into GPCR Drug Discovery & Development – Exploring GPCR-Ligand Interactions & Signaling Pathways with Binding & Functional Assays Access eBook
PathHunter Build Your Own β-Arrestin Assays Download Flyer
PathHunter Protein Translocation Assays: Track Cellular Movement of Proteins to Multiple Membrane Compartments Download Flyer
KILR Cytotoxicity Assays: Specifically Measure Target Cell Death in Co-Cultures Download Flyer
InCELL Target Engagement Assays: Universal Cell-Based Compound-Target Binding Assays Download Flyer
InCELL Pulse™ Target Engagement Kinase Reference Set Download Booklet